Picking mechanism for looms for weaving



Feb. 13, 1962 K. MQUNG 3,020,931

PICKING MECHANISM FOR LOOMS FOR WEAVING Fil ed Nov. 25, 1959 5 Sheets-Sheet 2 FIG. 2.-

I mvzmoa KHIN MOUNG ATTORNEY Feb. 13, 1962 K. MOUNG 2 PICKING MECHANISM FOR LOOMS FOR WEAVING Filed Nov. 23, 1959 5 Sheets-Sheet 3 INVENTOR KH l N MOUNG ATTORNEY Feb. 13, 1962 K. MOUNG PICKING MECHANISM FOR LOOMS FOR WEAVING I 5 Sheets-Sheet 4 Filed Nov. 23, 1959 INVENTOR KHIN MOUNG ATTORNEY Feb. 13, 1962 K. MOUNG 3,020,931

PICKING MECHANISM FOR LOOMS FOR WEAVING Filed Nov. 23, 1959 5 Sheets-Sheet 5 -F/ e. a.-

INVENTOR:

KHIN MOUNG ATTORNEY.

United States Patent 3,020,931 PICKING MECHANISM FOR LOOMS FOR WEAVING Khin Moung, 9 Shwegondine Road, Rangoon, Burma Filed Nov. 23, 1959, Ser. No. 854,618 4 Claims. (Cl. 139-147) This invention relates to improvements in picking mechanism for looms for weaving.

An analysis of known picking mechanisms for looms for weaving shows that the motion of the crankshaft is normally transmitted to the bottom or tappet shaft by the employment of large cast iron toothed gear wheels of one to two velocity ratio. By this means, the tappet shaft makes only one revolution when the crankshaft makes two revolutions. Then the tappet shaft, revolving at the reduced speed, is again made to produce a swift motion for generating such a strong striking force as to kick the shuttle with a speed of about 48 feet per second or a velocity, during shuttle acceleration, of about 30 feet per second.

To get the required force strong enough to generate the shuttle speed of about 48 feet per second, the power loom manufacturers all over the world up to now use jerkymotion producing devices, such as the picking tappets, the picking cams and the picking plates by fitting them to the tappet shaft which, as mentioned above, revolves with a speed only substantially one half that of the crankshaft. This is the prevailing method for generating the traditional picking motion for either overpick or underpick looms.

The object of the present invention is to use the crankshaft for generating the required shuttle acceleration which has an angular velocity substantially double that of the tappet shaft. Normally, the required shuttle acceleration is generated by the cone overpick tappet fitted to the bottom or tappet shaft, during degrees of the angular movement of the said tappet shaft. It shows that, if this acceleration is generated direct by the crankshaft, the duration of the angular movement will be double, i.e., degrees. It is known that the increase in the angular movement of a tappet to do a certain work and also the relative decrease in the angle of the slope of the said tappet are in direct ratio to the increase in the smoothness of the action of the said tappet, because of the reduced angle of friction of the said tappet in overcoming a certain resistance.

It will thus be found that the present invention for generating the picking motion direct by the crankshaft has achieved the above mentioned advantages.

According to the invention, the loom is provided with a crankshaft and a camshaft equipped for simultaneous motion by means of enmeshed toothed bevel gears or the like, the crankshaft carrying a fly wheel at each end and the camshaft carrying a cam at each end, each side of the loom having a picking lever capable of being actuated by the corresponding fly wheel, and each of said picking levers being pivotally connected to an auxiliary picking lever, the said auxiliary picking levers also being pivotally connected to respective auxiliary picking arms, the said auxiliary picking arms being connected to respective sliding bars sliding with the help of the respective cam on the camshaft, the connection being such that, when the two shafts are set into simultaneous motion, the picking lever is hit by the fly wheel at regular intervals, whereby the said picking lever is set into motion along with the auxiliary picking lever as a result of which a picking arm mounted on the auxiliary picking lever is shot out and translates its motion to the picking stick which picks the shuttle, the whole set of motions being repeated by mechanism on the other side of the loom resulting in the picking of the shuttle from both sides.

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The fly wheel may be provided with a projecting lug or anti-friction bowl which, on rotation of the fly wheel, hits the picking lever on its side near the top. This lever is pivotally connected to an auxiliary picking lever which moves forward and backward with the help of the auxiliary picking arm which is again connected by a connecting arm to a sliding bar sliding with the help of the cam on the camshaft. When the sliding bar moves forward and backward, the auxiliary picking arm and auxiliary picking lever also move forward and backward together with the main picking lever as a linked mechanism.

The ratio of the toothed bevel gears attached to crankshaft and camshaft respectively is l to 2. In the construction, the arrangement is such that, while one sliding bar is moving forward, the other is moving backward.

The invention will be described with reference to the accompanying drawings wherein:

FIG. 1 is a broken front elevational view showing the drive for the picking mechanism as applied to a loom;

FIG. 2 is a side elevational view of the construction shown in FIG. 1;

FIG. 3 is a top plan view of a part of the picking mechanism;

FIG. 4 is a front elevational view of the picking stick;

FIG. 5 is a top plan view of the bell crank picking lever;

FIG. 6 is a top plan view of a modified form of a picking arm;

FIG. 7 is a side elevational view of the modified picking arm shown in FIG. 6; and

FIG. 8 is a side elevational view of the bell crank and picker stick of the invention.

Throughout the specification and drawings, it will be understood that the disclosure includes the apparatus hereof as being provided on each side of the loom. In certain instances, the structure of only one side is defined, it being stipulated that duplicate instrumentalities and features thereof will be found on the opposite side.

In the construction shown in FIGS. 1 to 5, the loom is driven by a crankshaft 1. A bevel gear 2 is mounted on the crankshaft engaging a second bevel gear 3 mounted on a vertical shaft 4 driving a cam shaft 5 through further bevel wheels 6, 7. Fly gears 8, 8 are mounted on each end of the crankshaft 1 and earns 9, 9 are mounted on each end of the cam shaft 5 with lugs 10, 10a, 10 10 a, or antifriction bowls, limiting the translatory motion of sliding bars 11, 11 respectively. Main picking levers 12, 12 are mounted on the loom frame or loom sides to engage antifriction bowls 13, 13 projecting from the rim of fly wheels 8, 8 alternately. Main picking lever 12 is pivoted to an auxiliary picking lever 14 by a pin 15 and main picking lever 12 is pivoted to an auxiliary picking lever 14 by a pin 15 Auxiliary picking arms 16, 16 are pivotally connected by fulcrum pins 17, 17 to the auxiliary picking levers 14, 14 and, at their upper ends, the main arms 16, 16 are pivotally connected by pins 18, 18 and 19, 19 through connecting arms 20, 20 to one end of sliding bars 11, 11 Stud or bolts 21, 21 are affixed to each of the auxiliary picking levers 14, 14 and flat springs 22, 22 are provided to keep the picking levers 12, 12 in position. Adjustable picking arms 23, 23 are aflixed near the lower ends of the auxiliary picking levers 14, 14 Oil one side of the loom, a bell crank lever comprising two members 24, 25 is pivoted on pins 26 on the loom frame with the end of the members 25 on which a buffer 25 isprovided being capable of engagement by the picking arm 23. One end of a leather strap 26 i connected to the arm 24 of the bell crank lever, the other end being connected to a picking stick 27 to the upper end of which is aflixed a picker 28 for engaging the shuttle B. At one end of the leather strap 26, there is a loop 39 and a loop 40. The picking stick 27 is pivoted on a bracket 29 on the loom frame and on the other side of the loom identical parts are used.

When the crankshaft 1 rotates, the antifriction bowls 13, 13 on the fly wheels 8, 8 strike the upper ends of the main picking levers 12, 12 alternately causing the picking levers 12, 12 to move towards the cams 9, 9 alternately. The auxiliary picking levers 14, 14 and the arms 16, 16 which oscillate on the fulcrum pins 17, 17 move forward and backward with the help of the connecting arms 20, 20

The main picking lever 12 is a flexible extension of the auxiliary picking lever 14. These two levers 12, 14 are joined by the pin 15 which is rigidly fixed to the auxiliary lever 14. The picking lever 12 moves in an oscillating path on the auxiliary lever 14 on the pin 15. The free end of the flat spring 22 presses the picking lever 12 and keeps the lever in contact with the protruding stud or bolt 21 which is rigidly fixed to the auxiliary picking lever 14. The other end of the flat spring 22 is secured to the auxiliary lever by a screw 30.

When the picking lever 12 moves in the direction of the stud or bolt 21, it carries the auxiliary picking lever 14 with it as one rigid member. But when the picking lever 12 moves in the opposite direction, it becomes a flexible joint due to the tension of the fiat spring 22. Therefore, the backward movement of the picking lever 12 has no effect on the auxiliary lever 14. Only the forward movement of the picking lever 12 can move the auxiliary picking lever 14.

The connectingarms 20, 20 are linked to the sliding bars 11, 11 and also to the auxiliary picking arms 16, 16 by the pins 18, 18 and 19, 19 The sliding bars 11, 11 operates as a slotted bar mechanism as the camshaft 5 passes through slots 5a, therein.

These sliding bars 11, 11 move forward and backward alternately with the cams 9, 9 and the antifriction bowls 10, a, 10 which are in contact with the cams. The cams 9, 9 are affixed at the two ends of the camshaft 5. The antifriction bowls 10, 1011, 10 are aflixed to the sliding bars 11, 11 near the ends of slots 5a therein. The cam 9 is an edge cam with a curved edge, by the action of which it communicates motion to the rollers or antifriction bowls 10, 10a rigidly fixed near the two ends of the slot 5a in the sliding bar 11. The motion of the cam is in a plane at right angles to the shaft 5 to which the cam is secured. The rollers 10, 10a are kept in contact with the edge of the cam 9.

When the antifriction bowls or rollers come in contact with the working face 31 of the cam 9, these rollers together with the sliding bar are moved forward and backward alternately. When the rollers 10, 10a are in touch with the radial periphery of the cam 9, they are stationary for a quarter of a revolution of the cam. But when they are in contact with the working face 31, they are in motion either forward or backward.

The camshaft 5 also functions as a guide for the sliding bars 11, 11 as the shaft 5 passes through the slots 5a, in the sliding bars 11, 11 which are also guided by the brackets on the loom frames or loom sides.

Thus, the intermittent gorward and backward movement of the sliding bar 11 is obtained as the cam 9 rotates.

As a linked mechanism, the auxiliary picking arms 16, 16 on the fulcrum pins 17, 17 move forward and backward when the sliding bars 11, 11 move forward and backward. The two ends of the connecting arm 20 are affixed to the sliding bar 11 and the auxiliary picking arm 16 by the pins 18, 19 as a linked mechanism. The forward and backward movements of the auxiliary picking arms, 16, 16 are transmitted to the other auxiliary picking levers 14, 14 through springs 32, 32 mounted on rods 33, 33 which slide in the lugs 34, 34a on the auxiliary levers 14, 14 16 and 16 The motive force of picking arms 16, 16 is transferred to the auxiliary picking levers 14, 14 as follows:

The auxiliary picking levers 14, 14 and arms 16, 16 are mounted on the fulcrum pins 17, 17 which are spindles rigidly fixed to the loom sides. Although they both oscillate on the same spindle 17, they are independent. Both the auxiliary picking levers 14, 14 and the auxiliary picking arms 16, 16 pivot upon their respective fulcrum pins 17, 17 and accordingly pivot with each other. One can move freely without the other. But the function of the arm 16 is to give the required limited oscillatory movement to the auxiliary picking lever 14 with the help of the rod 33 and spring 32.

When the picking arm 16 moves forward, i.e. towards the cam 9, the auxiliary lever 14 also moves forward with the help of the lugs 34, 34a. But when the picking arm 16 moves backward from the forward position, the auxiliary picking lever 14 also moves backward along with the arm 16 due to the lugs 34, 34a, the rod 33 and the spring 32. In this manner, the picking arm 16 drives the auxiliary lever 14 through the rod 33 and spring 32. Due to the rod 33 and spring 32, the auxiliary picking lever 14 moves forward and backward together with the auxiliary picking arm 16.

The two cams 9, 9 are mounted on the two ends of the cam shaft 5 out of phase, i.e. opposite. By this means, the auxiliary picking levers 14, and 14 move as follows:

When the auxiliary picking lever 14 on one side of the loom moves forward, the other auxiliary picking lever 14 on the other side of the loom moves backward during one revolution of the cam shaft 5.

These cams 9, 9 are designed in such a way as to give the momentary pauses to the compound picking levers at the ends of their forward and backward movements. When the picking levers 12, 12 with their auxiliary levers 14, 14 stop for a moment at the ends of their backward movements, they are away from the circular moving paths of the revolving antifriction bowls 13, 13 on the fly wheels 8, 8 But when they stop for a moment at the ends of their forward movements, the ends of the picking levers 12, 12 are struck by the revolving antifriction bowls 13, 13 Thus the picking levers 12, 12 are in a state of motion as long as they are in contact with the revolving antifriction bowls 13, 13 The duration of this contact is adjusted by changing the positions of the antifriction bowls 13, 13 and the adjustable picking arms 23, 23 to get the optimum shuttle acceleration. When the picking lever 12 is struck, and pushed forward by the bowl 13, the auxiliary picking lever 14 also moves along with the picking lever 12 beyond the picking arm 16 although the picking arm 16 is at a stand-still momentarily due to the contact between the bowls 10, 10a and the radial portion of the cam 9. The picking lever 12 and auxiliary lever 14 move beyond the arm 16 on account of the rod 33 which slides in the holes in the lugs 34, 34a of the levers 14 and 16 under the action of the spring 32.

The picking levers 12, 12 are kept in their working position by the flat springs 22, 22 and the studs or bolts 21, 21 and at the same time the picking levers 12, 12 can be made to move backward without any movement of the compound auxiliary picking levers 14, 14 and arms 16, 16 when it is necessary to turn the crank shaft 1 in the reverse direction.

The adjustable picking arms 23, 23 are affixed near the lower ends of the auxiliary picking levers 14, 14 These transmit the motion of the auxiliary levers 14, 14 to pickers. The manner of transmitting the striking force from the bowl 13 to picker is explained below:

There are two sources of motive power to generate the radial movements of the picking lever 12 and auxiliary picking lever 14. The first source is the motion produced by the combined actions of the cam 9, the sliding bar 11. the arms 16 and the connecting arms 20,

as described above. The other source is the circular movement of the roller or antifriction bowl 13 attached to the fly wheel 8. The function of the first radial movements of the picking lever 12 and auxiliary lever 14 generated by the cam 9 and its component parts is to bring the picking lever and auxiliary lever 14 within the orbit of the circular movement of the bowl when the picking lever and auxiliary lever 14 move towards the cam 9 and also to keep the picking lever 12 and auxiliary lever 14 away from that orbit by their movement away from the cam 9. The roller or bowl 13 strikes the picking lever 12 when the picking lever 12 is at its forward position. But the picking lever '12 is out of the range of the circular movement of the bowl 13 when the picking lever 12 is at its backward position. In this manner, the roller or bowl '13 can strike the picking lever 12 once when the fly wheel 8 which carries the bowl 13 makes two revolutions because the gear ratio of the bevel gears 27 is 1:2.

The motion is arranged in such a way that, when the roller or bowl 13 strikes the end of the picking lever 12 during the time when the picking lever 12 is in its forward position, the picking lever 12 together with the auxiliary lever 14 moves beyond the distance of the movement generated by the auxiliary arm 16 as the auxiliary lever 14 is independent of the arm 16 and also as the auxiliary lever 14 is enabled to move beyond the arm 16 by the spring 32 on the rod 33 which slides in the lugs 34, 34a. At this instant, the picking arm 23 strikes the arm 25 of the bell crank lever. The picking arm 23 is affixed at the lower end of the auxiliary lever 14 by screws 35. The leather strap 26 joins the arm 24 of the bell crank lever at one end and the picking stick 27 at the other end. The picking stick 27 is fulcrumed on the loom frame. The picking stick 27 strikes the shuttle B through the leather picker 28 in known manner. The same arrangements are made for both sides of the loom.

In the modification shown in FIGS. 6 and 7, the picking arm 23a is rigidly fixed to the picker-rocking shaft or fulcrum 17 which is also rigidly fixed to the auxiliary picking lever 14, thus eliminating the bell crank lever. When the antifriction bowl 13 strikes the picking lever 12, the picking arm 23a moves as a rigid member as the fulcrum or picker-rocking shaft rocks in a bush 36 in a bracket 38, afiixed to the loom side. When the picking arm 23a moves, it pulls a short arm 37 connected to the picking stick 27 through a leather strap 26. The short arm 37 is rigidly affixed to the picking stick 27 at its lower end. The leather strap 26 is loose or slack when the picking lever 12 is away from the path of the rotating antifriction bowl 13 but is tightened when the picking lever 12 together with the auxiliary picking lever 14 is pushed forward together with the auxiliary picking arm 16 by the earn 9 to be struck by the antifrietion bowl 13 afl'ixed to the rim of the fly wheel 3 fitted to the crank shaft 1. The operation of the alternative method for striking the picking stick direct by the picking levers through the short arm and strap operates as above described by eliminating the bell crank lever.

I claim:

1. A picking motion for the shuttle of a weaving loom comprising, a crankshaft, a samshaft, gear means for transmitting motion from said crankshaft to said camshaft, a fly wheel mounted on said crankshaft, a cam mounted on said camshaft, a main picking lever capable of being actuated by said fly wheel, an auxiliary picking lever pivotally connected to said main picking lever, an auxiliary picking arm pivotable relative to said auxiliary picking lever, a slotted sliding bar reciprocated rectilinearly by said cam, said auxiliary picking lever being pivoted by the movement of said sliding bar, said auxiliary picking arm being pivoted by the movement of said sliding bar, an adjustable picking arm fixed to said auxiliary picking lever for movement therewith, and a picking stick engaged indirectly through a linkage with said adjustable picking arm for picking the shuttle across the loom, said sliding bar reciprocating said auxiliary picking arm and said auxiliary picking arm reciprocating said main picking lever and said auxiliary picking lever as said crankshaft and said camshaft are set into simultaneous motion, said fly wheel serving to drive said picking lever and auxiliary picking lever at timed intervals through a pivotal are greater than the pivoted arc imparted to said picking lever and said auxiliary picking lever by said auxiliary picking arm and said sliding bar.

2. In the mechanism as set forth in claim 1, with an anti-friction bowl on said fly wheel for engaging said main picking lever.

3. In the mechanism as set forth in claim 1, with the translatory motion of said sliding bar being limited by a pair of antifriction bowls, the bowls of said pair thereof being arranged at the ends of the slot of said sliding bar in contact with said cam, said cam having a contoured working face and communicating motion in a plane perpendicular to said camshaft and remaining in contact with the bowls of said pair thereof whereby the bowls of said pair thereof are pushed forward and backward with said sliding bar upon contact with the working face of said cam.

4. In the mechanism as set forth in claim 1, with a bell crank lever having one arm positively connected to said picking stick and a second arm engaged by said main picking lever.

References Cited in the file of this patent UNITED STATES PATENTS 2,760,522 Higgins Aug. 28, 6 

